I get a 401 error with that link, but when I visit it from a search engine it's fine. I think they may have blocked referrals from HN, so if you see that message, try copying-and-pasting the URL into a new tab / window / incognito window. I read this a while ago, and as other say, it's worth it.
Given the design, I reckon they might well be on a tiny hand-crafted server, in which case it makes sense. I seem to remember something similar the last time this was posted.
